Stereoscopic motion pictures have been displayed by simultaneously projecting overlapped right and left stereo images upon a screen through mutually extinguishing filters. The filters employed were colored filters such as red and green, or light polarizing filters disposed with their planes of polarization normal to each other.
Prior art devices for the projection of 3-D motion pictures used two projectors each having its own film strip and polarizer to project stereo images upon the screen, one projector having the film for right eye images and the other for left eye images. In the two projector systems, the images were difficult to synchronize, adjustment of the position of the overlapped images was time consuming and the image light intensities were frequently out of balance. Such systems also necessitated the additional expenses of twice as much film as standard motion pictures, extra handling in the projection booth, frequent monitoring, etc.
It has also been proposed to print left and right motion picture stereo pictures on a single film frame and to project them simultaneously using a single projector. Such stereo pictures may be printed side by side upon the film or one above the other. Mirrors and other optical devices have been employed to overlap the two images on the screen. These prior art optical devices, however, had substantial light loss resulting in lowered intensity of the projected images; were difficult to adjust, and required substantial modification of the standard motion picture projector.
It is an object of the invention to provide an improved 3-dimensional motion picture projection system.
Another object is to produce 3-dimensional displays from motion picture film that has been taken by conventional cameras, i.e., monocular cameras.
A further object is to achieve the foregoing objects with a structure of relative simplicity.
A specific object is to meet the above objects using conventional motion picture projection apparatus with relatively little modification.
A general object is to provide a relatively inexpensive optical device which is attached to existing projection equipment.
A further object is to utilize existing inventories of conventional film to create stereoscopic viewing effects, thereby enhancing the value of these film inventories.
It is a further object of the present invention to provide a stereo conversion system for standard motion picture projectors which will permit the projection of stereoscopie images from a single film strip with little light loss and a minimum of inconvenience and modification of the projector.
A further object of the present invention is to provide a compact, easily adjusted stereo conversion device for standard motion picture projectors, adaptable to the range of projection lenses of different foci, for the ranges of throw distance and screen sizes usually encountered in motion picture theaters.
Still another object of the present invention is to eliminate the distracting fringe images at the edges of the projected stereo images superimposed upon a screen.
A further object is to provide a single film strip containing single frames having conventional stereo or time delay stereo in any combination.
A further object is to provide a viewing device for editing conventional film strip taken with a monocular camera, for the purpose of selecting the best combination of stereo pairs from a given scene.
Other objects and various further features of novelty and invention will be apparent to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings which show, for illustrative purposes only, preferred forms and techniques of the invention: